docs: def Yu_France(m, x, rhol, rhog, mul, mug, D, roughness=0, L=1):
      r'''Calculates two-phase pressure drop with the Yu, France, Wambsganss,
      and Hull (2002) correlation given in [1]_ and reviewed in [2]_ and [3]_.
  
      .. math::
          \Delta P = \Delta P_{l} \phi_{l}^2
  
      .. math::
          \phi_l^2 = X^{-1.9}
  
      .. math::
          X = 18.65\left(\frac{\rho_g}{\rho_l}\right)^{0.5}\left(\frac{1-x}{x}
          \right)\frac{Re_{g}^{0.1}}{Re_l^{0.5}}
  
      Parameters
      ----------
      m : float
          Mass flow rate of fluid, [kg/s]
      x : float
          Quality of fluid, [-]
      rhol : float
          Liquid density, [kg/m^3]
      rhog : float
          Gas density, [kg/m^3]
      mul : float
          Viscosity of liquid, [Pa*s]
      mug : float
          Viscosity of gas, [Pa*s]
      D : float
          Diameter of pipe, [m]
      roughness : float, optional
          Roughness of pipe for use in calculating friction factor, [m]
      L : float, optional
          Length of pipe, [m]
  
      Returns
      -------
      dP : float
          Pressure drop of the two-phase flow, [Pa]
  
      Notes
      -----
  
      Examples
      --------
      >>> Yu_France(m=0.6, x=.1, rhol=915., rhog=2.67, mul=180E-6, mug=14E-6,
      ... D=0.05, roughness=0, L=1)
      1146.983322553957
  
      References
      ----------
      .. [1] Yu, W., D. M. France, M. W. Wambsganss, and J. R. Hull. "Two-Phase
         Pressure Drop, Boiling Heat Transfer, and Critical Heat Flux to Water in
         a Small-Diameter Horizontal Tube." International Journal of Multiphase
         Flow 28, no. 6 (June 2002): 927-41. doi:10.1016/S0301-9322(02)00019-8.
      .. [2] Kim, Sung-Min, and Issam Mudawar. "Universal Approach to Predicting
         Two-Phase Frictional Pressure Drop for Adiabatic and Condensing Mini/
         Micro-Channel Flows." International Journal of Heat and Mass Transfer
         55, no. 11-12 (May 2012): 3246-61.
         doi:10.1016/j.ijheatmasstransfer.2012.02.047.
      .. [3] Xu, Yu, Xiande Fang, Xianghui Su, Zhanru Zhou, and Weiwei Chen.
         "Evaluation of Frictional Pressure Drop Correlations for Two-Phase Flow
         in Pipes." Nuclear Engineering and Design, SI : CFD4NRS-3, 253 (December
         2012): 86-97. doi:10.1016/j.nucengdes.2012.08.007.
      '''
      # Actual Liquid flow
      v_l = m*(1-x)/rhol/(pi/4*D**2)
      Re_l = Reynolds(V=v_l, rho=rhol, mu=mul, D=D)
      fd_l = friction_factor(Re=Re_l, eD=roughness/D)
      dP_l = fd_l*L/D*(0.5*rhol*v_l**2)
  
      # Actual gas flow
      v_g = m*x/rhog/(pi/4*D**2)
      Re_g = Reynolds(V=v_g, rho=rhog, mu=mug, D=D)
  
      X = 18.65*(rhog/rhol)**0.5*(1-x)/x*Re_g**0.1/Re_l**0.5
      phi_l2 = X**-1.9
      return phi_l2*dP_l